In longwall mining employing a drum shearer, it has so far been found that a great deal of coal dust is produced on the entire working face when a coal wall is cut or falls.
In order to prevent the production of such coal dust, it has been proposed to sprinkle water on the spot producing such dust from the drum or to reduce the number of rotation of the drum. However, this is not a good solution to the aforesaid problem. In addition, scattering coal including coal dust is also produced when the coal wall is cut. However, there is no equipment for protecting the face of the mine workers from such coal dust and scattering coals, and hence, the workers have been protecting themselves by escaping to the intake air side or hiding under the shade of a machine or a support or the like.